# Study on the Tensile Properties and Influencing Factors of Superelastic SMAF-Reinforced PP/PVA-ECC Materials

## TL;DR

This study develops a cost-effective composite material using shape memory alloy and polymer fibers, showing improved tensile properties and potential for engineering applications.

## Contribution

The paper introduces a novel SMAF-ECC material with PP/PVA fibers and provides parametric guidance for optimizing its tensile performance.

## Key findings

- The optimal ECC mix with 0.8% PP and 1.2% PVA fibers achieves 4.88% ultimate tensile strain with reduced cost.
- SMAF volume and diameter significantly affect tensile performance, with 0.2 mm SMAFs at 0.2% volume showing the best results.
- SMAF-ECC specimens show 16.79% higher initial cracking stress and 20.85% higher ultimate tensile stress compared to pure ECC.

## Abstract

To develop a cost-effective shape memory alloy fiber-reinforced engineered cementitious composite (SMAF-ECC) with excellent mechanical properties, polypropylene (PP) fibers were used to partially replace polyvinyl alcohol (PVA) fibers to prepare the ECC matrix, and superelastic shape memory alloy fibers (SMAFs) were incorporated to fabricate a novel SMAF-ECC. Uniaxial tensile tests were systematically performed to characterize the tensile mechanical properties of the composites, focusing on the effects of SMAF volume content and diameter. The results indicate that the optimal base ECC mix proportion is 0.8 vol.% PP fibers and 1.2 vol.% PVA fibers, achieving an ultimate tensile strain of 4.88% (only a 4.69% reduction compared to pure PVA-ECC) while significantly reducing material cost without sacrificing superior ductility. SMAF volume content and diameter notably influence the tensile performance of SMAF-ECC, with the specimen containing 0.2 mm diameter SMAFs at 0.2 vol.% exhibiting the best performance: initial cracking stress, ultimate tensile stress, and ultimate tensile strain are enhanced by 16.79%, 20.85%, and 2.87%, respectively, compared to pure ECC. This study provides a theoretical basis and parametric guidance for the engineering popularization and application of cost-effective SMAF-ECCs.